Sydney airport launches online charity app

Sydney Airport is taking off as a jumbo-sized charity fundraiser.

And it's all down to its annual offload ... of lost property.

Thousands of unclaimed bits of booty ranging from iPods, surfboards, ukuleles and even microwave ovens raise a motza at the airport's charity auction.

Now it has now launched an online app to help decide which four good causes will receive the proceeds from the four-day sale in November.

With nearly 38 million passengers who travel through the airport each year, there's plenty of lost property that goes unclaimed.

Other items on the forgotten list include cameras, mobile phones, jewellery, alcohol and clothing.

Last year's auction raised a record $154,000 as part of the airport's $1.5 million contribution to the community, said Sydney Airport's chief executive Kerrie Mather said in a statement.

Previously the auction has supported The Salvation Army's Red Shield Appeal, Youth Off the Streets, the Australian Kookaburra Kids Foundation among others over the years.